A dead cat in the in-tray. That’s what Greenpeace called the newly elected Australian government’s inheritance of a proposal to build the largest coal port in the world at Abbot Point in the northeastern state of Queensland. A decision is required, and the stakes couldn’t be any higher.

On one side lies the opportunity to efficiently exploit nine proposed megamines in the Galilee Basin and the thousands of jobs and billions of export dollars that entails. On the other lies the integrity of the World Heritage–listed Great Barrier Reef — a series of 3,000 individual reef systems that collectively rank as the largest, most complex and diverse mass of living organisms on earth.

Such is the risk posed to the ecosystem by Abbot Point and 17 other proposed ports on the Queensland coast that the U.N.’s scientific body UNESCO is mulling the idea of placing the Great Barrier Reef on its World Heritage in-danger list. There, it would join Florida’s Everglades National Park, Syria’s bombed ancient city of Aleppo and 42 other heritage-listed sites threatened by war, natural disasters or unchecked development.

“To have one of the seven natural wonders of the world appear on that list would be a massive international embarrassment and shame,” Greens Senator Larissa Waters tells TIME. “Most people I speak to on the street can’t believe the government is putting the interests of foreign mining companies ahead of the protection of our reef.”

According to the Australian Institute of Marine Science, the Great Barrier Reef has lost half its coral cover since 1986. Fifty percent of that loss is attributable to storm damage while the other half has been eaten by crown-of-thorn starfish, formidable echinoderms covered in venomous spines that can each consume up to 6 sq m of coral a year.

It’s against this backdrop that UNESCO is questioning whether the huge dredging activities associated with the construction of new deep-sea ports will prove to be the straw that breaks the Great Barrier Reef’s back. In 2011, Australia failed to notify the World Heritage Committee about a port-expansion project at Curtis Island, 635 km south of Abbot Point, where 21 million cubic meters of sand and mud were dredged and dumped on the ocean floor. A team of UNESCO investigators that visited the site last year found water quality had declined and put the Queensland government on notice, telling it that remedial measures would have to be undertaken to prevent the area being listed as endangered. That follows the discovery by the Gladstone Fishing Research Fund of algal blooms and acidity variations in the water, major outbreaks of diseases in turtles, dolphins and dugongs (sea cows), and above-average metal counts in the blood of fish.

The environmental footprint of the proposed expansion at Abbot Point is significantly smaller than the one at Curtis Island; only 3 million cubic meters need to be dredged. The state-owned port operator, North Queensland Bulk Ports Corp. (NQBP), has also been talking with commercial fishermen to find the best place to dump the spoil. So far, though, they’ve failed to reach a consensus. The fishermen say anywhere the sludge is dumped will negatively impact water quality and fish stocks — sentiments that are shared by tourism operators at the nearby Whitsunday Islands, a sun-kissed archipelago that’s the jewel on the crown of Queensland’s $5 billion tourism sector.

“The people working on boats here have all seen the loss of coral and decreased water quality,” says Keith Roberts of Whitsunday Catamarans, one of the 61,000 people who make a living showcasing the Great Barrier Reef’s 600 types of coral, 1,625 fish species, 3,000 types of mollusk and 1,500 varieties of sponge to tourists. “Now they want to dump 3 million cubic meters of sludge on sea-grass beds where dugongs live. We feel very let down by the government.”

Roberts also highlights the perils of having hundreds more coal ships passing through the Great Barrier Reef every year “muddying up shallow waters with very large propellers and smashing into reefs like that Chinese vessel,” he says in reference to Shen Neng 1, a Chinese cargo ship that ran aground near Keppel Bay Islands National Park in 2010, releasing 4 tons of fuel into the water and destroying 3 km of coral reefs.

NQBP spokeswoman Mary Steele claims it’s “offensive when groups claim they have exclusive rights over the well-being of the Great Barrier Reef.” In the past 21 years, she maintains the company has carried out 19 separate dredging operations without incident in the area, and in each case the predicted impacts were greater than the actual impacts.

“Six of Australia’s most important ports have been operating and expanding along the Great Barrier Reef for over 50 years and only invested millions of dollars in environmental management,” Steel says. “I would like to know what these groups that criticize us have invested.”

Adds Tony Doyle, a real estate agent in the nearby town of Bowen: “I’ve lived here all my life, and I’ve been fishing here all my life. But I’ve never seen any kind of negative impact from dredging. I was out on a boat last weekend, and the fish were practically jumping out of the water.”

Acting Queensland Premier Jeff Seeney tells TIME that “alarmist claims have been made about the Great Barrier Reef for years.” He says his government “is committed to achieving world’s best practice [and has] significantly scaled back the original expansion proposal for Abbot Point,” adding that the decision is now in the hands of the new federal government.

At the time of writing, that decision is looking more and more like a simple rubber stamp. Since winning the Sept. 8 general election on the wave of a probusiness, promining sentiment, newly minted Prime Minister Tony Abbott has announced the scrapping of the Climate Commission, the Climate Change Authority and the carbon tax. That news was ill-received on the Whitsundays this weekend, where British national Ben Southall, winner of the famous 2009 Best Job in the World competition and now a resident of Queensland, was filming marine life for the state’s tourism authority.

“It’s a fine balance between supporting the Australian economy and looking after the long-term health of the Great Barrier Reef,” Southall says. “But we have an amazing World Heritage site right now, and if we don’t do everything we can to protect it, it may not be around for me to show it to my grandchildren.”